This invention relates to amplifier circuits and, in particular, to detection amplifiers used to detect information readout from dynamic semiconductor memory array systems.
Many of today's detection amplifiers, such as the common emitter differential amplifier, employ voltage sensing techniques. Typically, a voltage signal is applied to the base input terminal while the complement signal, or a reference signal, is applied to the other base input terminal. This circuit has the nominal advantage of having relatively high input impedance which does not load down the source of the input signals.
In many of today's dynamic MOS memory array systems, the output signals are pulses of charge or relatively low current levels. The high input impedance of common emitter differential amplifier coupled with the relatively large capacitance associated with the output bit lines of these memories results in a relatively large RC time constant which degrades the response time of the amplifier.